Specifies the surface density of a PolygonMesh in the M direction.
Supported platforms: Windows only
Read-only: No
Type: Integer
An integer value between 2 and 256.
The M surface density is the number of vertices in the M direction for PolygonMesh objects that are of the following types: acQuadSurfaceMesh, acCubicSurfaceMesh, or acBezierSurfaceMesh.
The initial value for this property is derived from the value in the SURFU system variable + 1. Therefore, if the current value of SURFU is 6, the MDensity for a mesh after a surface fit operation would be 7. To perform a surface fit operation on a mesh, change the mesh type using the Type property.
VBA:
Sub Example_MDensity()
' This example creates a 4 X 4 polygonmesh in model space.
' It then changes the type of polymesh, and finds the
' number of points in the 'M' direction.
Dim meshObj As AcadPolygonMesh
Dim mSize, nSize, count As Integer
Dim points(0 To 47) As Double
' Create the matrix of points
points(0) = 0: points(1) = 0: points(2) = 0
points(3) = 2: points(4) = 0: points(5) = 1
points(6) = 4: points(7) = 0: points(8) = 0
points(9) = 6: points(10) = 0: points(11) = 1
points(12) = 0: points(13) = 2: points(14) = 0
points(15) = 2: points(16) = 2: points(17) = 1
points(18) = 4: points(19) = 2: points(20) = 0
points(21) = 6: points(22) = 2: points(23) = 1
points(24) = 0: points(25) = 4: points(26) = 0
points(27) = 2: points(28) = 4: points(29) = 1
points(30) = 4: points(31) = 4: points(32) = 0
points(33) = 6: points(34) = 4: points(35) = 0
points(36) = 0: points(37) = 6: points(38) = 0
points(39) = 2: points(40) = 6: points(41) = 1
points(42) = 4: points(43) = 6: points(44) = 0
points(45) = 6: points(46) = 6: points(47) = 0
mSize = 4: nSize = 4
' Create a 3Dmesh in model space
Set meshObj = ThisDrawing.ModelSpace.Add3DMesh(mSize, nSize, points)
' Change the viewing direction of the viewport to better see the polymesh
Dim NewDirection(0 To 2) As Double
NewDirection(0) = -1: NewDirection(1) = -1: NewDirection(2) = 1
ThisDrawing.ActiveViewport.direction = NewDirection
ThisDrawing.ActiveViewport = ThisDrawing.ActiveViewport
ZoomAll
' Change the type of mesh. (MDensity is not valid for acSimpleMesh type.)
meshObj.Type = acQuadSurfaceMesh
meshObj.Update
ThisDrawing.Regen acActiveViewport
' Find the MDensity for the mesh
Dim currDensity As Integer
currDensity = meshObj.MDensity
MsgBox "The MDensity for the mesh is " & meshObj.MDensity, , "MDensity Example"
End Sub
Visual LISP:
(vl-load-com)
(defun c:Example_MDensity()
;; This example creates a 4 X 4 polygonmesh in model space.
;; It then changes the type of polymesh, and finds the
;; number of points in the 'M' direction.
(setq acadObj (vlax-get-acad-object))
(setq doc (vla-get-ActiveDocument acadObj))
;; Create the matrix of points
(setq points (vlax-make-safearray vlax-vbDouble '(0 . 47)))
(vlax-safearray-fill points '(0 0 0
2 0 1
4 0 0
6 0 1
0 2 0
2 2 1
4 2 0
6 2 1
0 4 0
2 4 1
4 4 0
6 4 0
0 6 0
2 6 1
4 6 0
6 6 0
)
)
(setq mSize 4
nSize 4)
;; Create a 3Dmesh in model space
(setq modelSpace (vla-get-ModelSpace doc))
(setq meshObj (vla-Add3DMesh modelSpace mSize nSize points))
;; Change the viewing direction of the viewport to better see the polymesh
(setq NewDirection (vlax-3d-point -1 -1 1))
(setq activeViewport (vla-get-ActiveViewport doc))
(vla-put-Direction activeViewport NewDirection)
(vla-put-ActiveViewport doc activeViewport)
(vla-ZoomAll acadObj)
;; Change the type of mesh. (MDensity is not valid for acSimpleMesh type.)
(vla-put-Type meshObj acQuadSurfaceMesh)
(vla-Update meshObj)
(vla-Regen doc acActiveViewport)
;; Find the MDensity for the mesh
(setq currDensity (vla-get-MDensity meshObj))
(alert (strcat "The MDensity for the mesh is " (itoa currDensity)))
)